AU730226B2 - A ladder stabilising assembly - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT r r Name of Applicant: Actual Inventor: Address for Service: Christopher Peter BARFIELD As above CULLEN

CO.,

Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, QId. 4000, Australia.

Invention Title: A LADDER STABILISING ASSEMBLY The following statement is a full description of this invention, including the best method of performing it known to me: 2 A LADDER STABILISING ASSEMBLY This invention relates to a ladder stabilising assembly which can be attached to a ladder and which can stabilise the ladder against sideways movement.

Ladder stabilising assemblies are known in the art and are used to stabilise ladders and especially long ladders (4m or longer) against sideways tipping. These known assemblies have a pair of support legs each leg being attached to the ladder stile. The support legs have a lower end with a ground engaging foot member and the upper end is usually fastened to the o ladder stile.

o A disadvantage with current ladder stabilising assemblies is in the attachment of the assemblies to the ladder. This is because the ladder assemblies still need to be adjustable to compensate for uneven ground or to allow the support legs to swing out widely from the ladder stiles or to be close 15 into the ladder stiles. To date, there is not a quick and easy method by which a ladder stabilising assembly can be quickly attached to a ladder but where the assembly can also be easily adjusted.

One type of known ladder stabilising device has a toothed rack which must be fastened to each ladder stile and a lever on an upper part of 20 the support leg engages with the toothed rack at various positions thereby providing a measure of adjustability. However, in this arrangement, the ladder stiles must be modified to accommodate a complicated toothed rack assembly.

Another type of ladder stabiliser uses collars which slide along the stiles. The collars can be clamped in place using wing nuts. The collars are however not suitable for all types of ladders and various different collars are required for various different types of ladder stiles. Also, the collars are clamped in place and, apart from this clamping action, there is no positive engagement such as a pin which passes into a socket whereby it is almost impossible for the stabilising assembly to inadvertently become loose.

More simpler types of ladder stabilising assemblies have pivotally attached support legs which are not adjustable along the ladder stile and this type of stabilising assembly is rather restricted in use.

Another disadvantage with existing ladder stabilising assemblies is that the support legs can only pivot inwardly and outwardly in the plane of the ladder. However, there is an advantage in having a stabilising assembly where the support legs, as well as pivoting in this manner, can also move forwardly and rearwardly of the ladder to provide a greater degree of stability.

The present invention is directed to a stabilising assembly for a ladder which may at least partially overcome the abovementioned disadvantages or provide the public with a useful or commercial choice.

10 aIn one form, the invention resides in a ladder stabilising -assembly for a ladder of the type having hollow ended rungs, the assembly oo:o having at least one support leg which has a lower end adapted to contact the •ground, an upper end, and a finger operatively attached to the support leg and which can be pushed into a said hollow ended rung to attach the 15 assembly to the ladder.

In another form, the finger is pivotally attached adjacent the upper end of the support leg, and an intermediate support brace is provided which has one end pivotally attached to the support leg intermediate its ends and the other end attached to the ladder stile.

V. 20 In another form of the invention, there is provided a ladder ";;;.stabilising assembly having at least one support leg which is a lower end adapted to contact the ground, the support leg being attached to the ladder stile, the support leg being able to pivot towards and away from the ladder stile and also able to move in front and/or behind the plane of the ladder.

In the first form of the invention, the ladder stabilising assembly has a finger which can be pushed into the hollow end rung of a ladder having such rungs. This arrangement is simple in operation yet does away with the need for ratchet mechanisms or other complicated clamping arrangements.

The ladder assembly is adjustable as the finger can be pushed into any desired rung along the ladder stile.

Ladders having open ended rungs are well-known. The rungs are usually formed from tubular metal such as aluminium and in one known type of assembly operation, the rungs are pushed through the ladder stile wall and the ends of the rungs are then swaged over to lock against the ladder stile. The rungs are hollow to lessen the weight of the ladder yet are extremely strong. The first form of the invention takes advantage of the hollow rungs by making these the adjustment points for the ladder stabilising assembly.

The assembly has at least one support leg and typically has a support leg on each ladder stile. The support leg has a lower end which contacts the ground and this end may be provided with a foot or like member which may be pivotally attached to the support leg.

-The finger may comprise a metal or other type of rigid strong member which can be pushed or hammered or otherwise inserted into a ladder rung. The finger can be attached to an uppermost part of the support leg and can be pivotally attached relative to the support leg such that when S: 15 the finger is pushed into the ladder rung, the support leg can pivot inwardly and outwardly from the ladder stile and about the pivot pin.

SiThe finger itself should be configured to approximate the internal configuration of a ladder rung. The internal configuration of the ladder rung is either O-shaped or D-shaped and the finger should have a 20 configuration to suit. The finger should be sized to fit into the rung without being too loose, but on the other hand the finger should not be extremely difficult to push into the rung or almost impossible to remove from the rung.

Therefore, a snug fit is envisaged.

In another form of the invention, an intermediate support brace is provided which extends above the lower end of the support leg but below where the finger is attached to the support leg. The intermediate support brace has one end pivotally attached to the support leg and the other end attached to the ladder stile. It is preferred that the other end is also pivotally attached to the ladder stile. This pivoting arrangement allows the finger to be removed from the ladder rung and allows the stabilising assembly to be collapsed against the ladder stile which means that it can be permanently attached to the ladder and only extended when required.

In another form of the invention, the finger may be pivotally and swivably attached relative to the support leg which allows the support leg to move forwardly and rearwardly of the ladder as well as towards and away from the ladder stile. In this arrangement, a support brace may also be provided with the support brace being pivotally attached such that it can also move forwardly and rearwardly of the ladder.

An embodiment of the invention will be described with reference to the following figures in which Figure 1 shows an extension ladder having a ladder stabilising .10 assembly according to an embodiment of the invention.

SFigure 2 shows one support leg in greater detail.

Figure 3 is an exploded view of the support leg of Figure 2.

Figure 4 illustrates an alternative finger configuration.

Figure 5 illustrates an alternative type of support leg having a 15 length adjustable foot.

Figure 6 illustrates an alternative support leg which can move in front of and behind a ladder as well as towards and away from the ladder •o stile.

Referring initially to Figure 1, there is shown a ladder 10 which is an extension ladder and which can extend to up to 6m or more. The ladder, like conventional ladders, has a pair of stiles 11, 12 and an array of rungs 13. The ladder itself is entirely conventional. These long ladders have a fairly narrow foot base and therefore stabilisation of the ladder is required.

Figure 1 illustrates a ladder stabilising assembly which in the embodiment consists of two support legs 14, 15 each leg having a lower end 16 on which is provided a pivoting foot (see Figure The support legs are typically between 1 to 3m long although this can vary depending on the size of the ladder to be supported. The support legs in the embodiment are formed from metal box section although the legs can also be formed from other materials or channel section, solid rod and the like. The legs however must be sufficient strong and rigid to stabilise the ladder.

Each support leg 14, 15 is provided with a finger 17. Finger 17 is a solid or hollow metal member which is pivotally attached to its respective support leg via a pivot pin 18 with the pivot pin being away from the rear end 19 of finger 17. The configuration of finger 17 is such that it can be pushed or lightly hammered into the hollow end of rungs 13.

Hollow ladder rungs are usually of an O-shaped configuration or a D-shaped configuration and Figure 3 illustrates a D-shaped finger 17 while Figure 4 illustrates the alternative O-shaped finger 17A. If necessary, finger 18 can be lightly hammered into the rung by striking end 19 of the finger with a hammer.

10 In the embodiment, the stabilising assembly has an intermediate support brace 20 which is pivotally attached both to the respective ladder stile 11 and to the respective support leg 14, Figure 3 illustrates support brace 20 in greater detail. The support brace includes an elongate rigid strut 21. One end of strut 21 is 15 fastened to a hinge 22 with hinge 22 fastened to support leg 15. In this arrangement, strut 21 can hinge or pivot against and away from support leg The other end of strut 21 is also fastened to a hinge 23 and hinge 23 is fastened to ladder stile 11 or 12 with the rear wall of the ladder stile having a backing strengthening plate 24 to which hinge 23 is attached. Thus, support brace 20 is permanently attached to the ladder stile and to the support leg, and in this embodiment the ladder stabilising assembly is permanently attached to the ladder.

When not in use, support leg 15 sits up against the lower end of ladder stile 11 or 12 and it can be clipped in place by a clip 25 which is attached to the ladder stile and which clips about support leg When ladder stabilising is required, each support leg 15 can be pulled out of its clip 25 and finger 17 can be pressed into a desired ladder rung. Support brace 20 prevents the support leg 15 from pivoting out too far.

It is not necessary for the finger 17 of each support leg to be in the same rung. Indeed, for uneven ground, the finger of one support leg may be in a rung above or below the finger of the other support leg.

Figure 5 shows a variation to the support leg 15 which variation is basically that the foot 26 is itself height adjustable by consisting of a threaded rod 27 which threading engages with an internal nut (not shown) in support leg 15. This allows for fine height adjustment of the support leg if the ladder rungs 13 are perhaps too far apart.

Figure 6 illustrates a different type of support leg. In this arrangement, support leg 30 has an upper pivot pin 31 which attaches to a swivel rod 32 with finger 33 being swivably attached to swivel rod 32 via a pivot bolt 34. Thus, in this arrangement, support leg 30 can pivot and swivel relative to finger 33. As well, support brace 35 is hingedly attached via hinge lo t• 36 to support leg 30 while the other end of the support brace is hingedly attached via hinge 37 to the ladder stile and to a strengthening backing plate o*oo 38 behind the ladder stile. Hinge 37 is pivotally attached to support brace via vertical pivot pin 39 which means that the support brace can pivot up and down but can also swivel about pivot pin 39.

15 The arrangement of Figure 6 is one which allows the support leg to move in front of and behind of the ladder to provide additional support.

In the case of a ladder which does not have hollow rungs, finger 17 can be removed and an attachment plate can be attached to the ladder stile. This will still allow the stabilising assembly to swing forwardly and 20 rearwardly of the ladder (using the arrangement illustrated in Figure 6) and will still allow the ladder arrangement to collapse against the ladder stiles.

It should be appreciated that various other changes and modifications can be made to the embodiment described without departing from the spirit and scope of the invention as claimed.

Claims (4)

1. A ladder stabilising assembly for a ladder of the type having hollow ended rungs, the assembly having at least one support leg which has a lower end adapted to contact the ground, an upper end, and a finger pivotally attached adjacent an upper end of the support leg and which can be pushed into a said hollow ended rung to attach the assembly to the ladder.

2. The assembly of claim 1, wherein an intermediate support brace is provided which has one end pivotally attached to the support leg intermediate its ends and the other end attached to the ladder stile. 10to

3. The assembly of claim 1 or claim 2 substantially as hereinbefore described with reference to the drawings.

4. Each and every novel feature of the invention. DATED this 8 th day of December 1999 Christopher Peter BARFIELD 15 By his Patent Attorneys "CULLEN &CO. S